PSI - Issue 14

Mohd Tauheed et al. / Procedia Structural Integrity 14 (2019) 354–361 Mohd Tauheed/ Structural Integrity Procedia 00 (2018) 000–000

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Fig. 7. Geometry of the SLS specimen

Experimental Predicted_without_adhesive Predicted_with_adhesive

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Moving jaw

SLS specimen

Failure Load, N

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Displacement, mm

Fig. 8. (a) Experimental setup for SLS test (b) Comparison between predicted and experimental load-displacement curve of single lap joint

5. Conclusions This work aimed at extracting the cohesive laws of composite adhesive joints using the direct method and to assess the use of these cohesive laws in predicting failure strength of joints under mixed-mode loading. Fracture tests with DCB and ENF specimens along with DIC technique was used to extract the mode I and mode II TSLs, respectively. It was found that the experimentally determined TSLs can be closely approximated with the bi-linear TSL. These bi linear TSLs were then used in a FE model based on cohesive zone modelling to predict the failure response of SLS joints (mixed-mode loading). The FE predicted failure response of the SLS joints closely matched with the experiments on SLS joints, thereby validating the FE model and the extracted TSLs. The FE model further showed that the compliant adhesive layer has an insignificant effect on the failure response. Acknowledgements The authors acknowledge the financial support received from the Science and Engineering Research Board (SERB), Government of India under Grant No. ECR/2015/456. References Constante, C. J., Campilho, R. D.S.G., Moura, D. C., 2015. Tensile Fracture Characterization of Adhesive Joints by Standard and Optical Techniques” Engineering Fracture Mechanics 136, 292–304. Patil, O. R., Ameli, A., Datla, N. V., 2017. Predicting Environmental Degradation of Adhesive Joints Using a Cohesive Zone Finite Element Model Based on Accelerated Fracture Tests. International Journal of Adhesion and Adhesives 76, 54–60. Balzani, C., Wagner, W., Wilckens, D., Degenhardt, R., Büsing, S., Reimerdes, H.G., 2012. Adhesive Joints in Composite Laminates—A Combined Numerical/Experimental Estimate of Critical Energy Release Rates. International Journal of Adhesion and Adhesives 32, 23–38. Carvalho, U. T.F., Campilho, R. D.S.G., 2017. Validation of Pure Tensile and Shear Cohesive Laws Obtained by the Direct Method with Single Lap Joints. International Journal of Adhesion and Adhesives 77, 41–50. Campilho, R.D.S.G., Banea, M.D., Neto, J.A.B.P., da Silva, L.F.M., 2013a. Modelling Adhesive Joints with Cohesive Zone Models: Effect of the Cohesive Law Shape of the Adhesive Layer. International Journal of Adhesion and Adhesives 44, 48–56.